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Using the state of reefs for Anthropocene stratigraphy: An ecostratigraphic approach

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(Excerpts from text) … Reefs as ecosystems have shown pronounced evolutionary changes as well as marked adaptation to distinct but changing ecological reef settings, and they hence were prone to reflect large-scale synchronous global impacts as well as regional ecological changes. Therefore, extensive episodes of global reef decline during major Earth-history global extinction events, followed by millions of years of reef recovery times, provide excellent global correlation markers. … Although most present tropical reefs are dependent on photosymbiosis, letting them flourish within a narrow range of warm, superoligotrophic (with low nutrients and high dissolved oxygen) waters, there are still some modern reefs that, from their organic composition and environmental adaptations, resemble geologically much older reefs and hence are termed ‘atavistic’ Such reefs are composed of more robust, more resilient, more adaptable or even ‘Lazarus’-type relic taxa, which allow them to thrive in high-sediment and - nutrient settings, deeper waters and generally unstable environmental regimes. Atavistic reefs and Lazarus-reef taxa can be expected to become more common as the Anthropocene progresses … Ecostratigraphic Scenario 1 … Despite many efforts to support coral reefs, there is general scientific agreement that under ‘business as usual’ conditions there will be a global demise or severe reduction of coral reefs somewhere between the middle and end of the 21st century. … Earth history is no comfort in this respect, because recovery following global shallow- water reef extinctions during the Phanerozoic took place over many millions of years Ecostratigraphic Scenario 2: … Some reef researchers see the evolutionary and epigenetic adaptivity of corals and other reef organisms as much larger than previously thought, believing that especially in a combined effort of (1) keeping atmospheric CO2 below 450 ppm, (2) extensive management of reefs (in relation to overfishing, eutrophication, sediment runoff and other pollution as well as tourist or shipping damage) via marine parks, and (3) ‘assisted’ approaches to enlarge resilience of coral reefs, there might be progress towards enhancing coral-reef development during the future Anthropocene … under this low- emission scenario, coral reefs would experience an increase of SSTs from 0.30°C to 0.68°C within the period from 2010 to the end of the 21st century. The entire range of temperature increase, including the past century, would still be near or above 1°C, which is considered to be critical to coral reefs, but at least some of them could continue to exist. … Living with the vale of tears: The future of Anthropocene coral reefs relies on reducing emissions of CO2 from fossil fuels and on new forms of governance, management and educational concepts to limit the human impact on coral reefs. However, it may also rely on protecting and supporting exceptional, in part atavistic reef types that so far thrive only in places different from the classic modern oligotrophic reef settings and can grow under elevated sediment and nutrient influx … reefs will only have a chance if (a) strong management (including new protection and social-management schemes, as also outlined by Hughes et al. 2017b) is implemented and (b) emissions from fossil fuels stop around 2050. But even in this positive case, reefs would have to cross a critical ‘vale of tears’ phase (Figure 3.4.3b). Such specialised reefs would only have a chance to survive if allowed to adapt to the new conditions in a natural way or helped via human- assisted adaptation. Such reefs would be of lower diversity, having fewer ecological niches, and would probably be short-lived and patchy. They would most likely not play an important role in coastal protection and possibly only a reduced role in supporting fish stocks. However, after such a phase of volatility and adaptation, reefs might hopefully recover in the late 22nd or 23rd century, possibly forming large, structured reefs again, though different in taxon structure relative to Holocene ones.
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3.4 Using the State of Reefs
for Anthropocene Stratigraphy:
An Ecostratigraphic Approach
Reinhold Leinfelder
3.4.1 General Considerations
Throughout Earth history, reef organisms have only
minor potential for biostratigraphic use, with
exceptions such as some Paleozoic rugose corals and
several Cretaceous reef-building rudist bivalves.
However, reefs as ecosystems have shown
pronounced evolutionary changes as well as marked
adaptation to distinct but changing ecological reef
settings, and they hence were prone to reect large-
scale synchronous global impacts as well as regional
ecological changes.
Therefore, extensive episodes of global reef decline
during major Earth-history global extinction events,
followed by millions of years of reef recovery times,
provide excellent global correlation markers.
Although the causes for these global extinctions are
not all fully understood, elevated sea surface
temperatures (SSTs) combined with a strong lowering
of marine seawater alkalinity and sometimes turnover
of oceans into an oxygen-decient state appear to
be associated with most, if not all, extinction events.
In most cases extensive volcanism (at times perhaps
triggering additional methane clathrate degassing and
blowouts from ocean sediments) was related to the
extinction events, with additionally an asteroid
impact being substantiated for the Cretaceous/
Paleogene boundary. Reef recovery rates were very
slow, of a minimum duration of a few million years
and a maximum of 140 million years in coral-rich,
open-water tropical reefs, extending from the
midLate Devonian extinction to the Late Triassic
onset of shallow-water scleractinian reefs
(Figure 3.4.1). Other reef types, such as richthofeniid
reefs, muddy reefs with a low-diversity fauna of
corals or deeper-water mounds rich in phylloid algae,
siliceous sponges, calcisponges and bryozoans
continued to grow during this extensive gap. This
might also be important for reassessing reef growth
during the recent episode of Anthropocene reef crisis
(Stanley 2001a, b).
1
Less often used for stratigraphic purposes are
shorter-term changes in the growth episodes,
architecture and community structure of reefs, as
controlled by sea-level change. Reef expansion
episodes are most typically associated with relative
sea-level rises. During times of high sea level, reefs
may be covered by other sediments, while when sea
levels are low, reefs are often exposed subaerially and
cease to grow. Such dynamic patterns can be highly
signicant for deciphering sea-level changes lasting
~0.5 to 3 Ma or less, governing available space for
reef growth, wave energy level and the inux of
siliciclastic sediments and nutrients from terrestrial
areas. The last of these may result in regional shallow-
water oxygen depletion and cessation of reef growth.
This relationship has made reefs an important
ecostratigraphic tool for constraining sea-level
history in ancient tropical marine environments,
especially during the Mesozoic, where the new
scleractinian coral reefs thrived in a great variety of
settings next to other reef types such as siliceous
sponge reefs and microbial reefs, each having its
distinct environmental framing. The dependence of
reef organisms and reef types on particular
environmental settings does not preclude using them
for stratigraphic correlation, so long as there is a good
appreciation of controls on reef parameters and
how to model them in an ecostratigraphic context
(Hofmann 1981; Sokolov 1986; Oloriz et al. 1995).
Consequently, ancient reefs have been used to
constrain global sea-level histories with generally
good results. Their geometric growth patterns,
1
For overviews of reef evolution and extinctions through Earth
history, see Wood, (1999), Leinfelder and Nose (1999), Stanley
(2001a, b) and Veron (1995, 2008); for global extinction
events, see also Buggisch (1991), Copper (2001), Flügel and
Senowbari-Daryan (2001), Hautmann (2012) and Clarkson
et al. (2015).
128 3.4 Using the State of Reefs for Anthropocene Stratigraphy: An Ecostratigraphic Approach
Personal copy (proof, with final corrections included)
Published in: Jan Zalasiewicz, Colin Waters, Mark Williams, Colin Summerhayes, (eds), (2019): The Anthropocene as a Geological
Time Unit. A Guide to the Scientific Evidence and Current Debate, Cambridge University Press, ISBN 9781108475235
have had only
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Figure 3.4.1 The past, present and possible future of reefs.
(a) Coral-rich reefs through time. Growth episodes (highs), major Earth-history extinction events (red labelled lines),
reef recovery times (red rectangles); long horizontal line is the 140-million-year-long gap of tropical, coral-rich reefs.
Numbers are millions of years. Precambrian not to scale. Modied after Veron (2008).
(b) The concept of increasing overall reef complexity, based on subsequent addition of reefal building blocks, which persisted
throughout Earth history. Note that modern tropical coral reefs still contain microbial crusts within reef caves and include
demosponges as well as calcifying sclerosponges (based on Leinfelder & Nose 1999).
(c) After a number of changes from the Proterozoic (stromatolite reefs) to the Mid-Paleozoic (possibly already
including photosymbiontic reef organisms, chiey stromatoporoids and some tabulate corals) and the long gap of tropical
coral-rich reefs from the latest Devonian to the Late Triassic, the width of reef windows, as dened as the maximum
available space of reef settings, became probably largest during the Jurassic, with microbialite reefs and a great variety of
different siliceous sponge reefs and tropical coral reefs co-occurring. After optimising the photosymbiontic system and with
the onset of coralline algae conquering high-energy settings, modern tropical coral reefs are in a much narrower,
more superoligotrophic window than, e.g., Jurassic coral reefs. For the Anthropocene, a best-case scenario is shown, with
reef compositions changing and relic reef types that are adapted to higher nutrients, more runoff, elevated temperatures
and reduced alkalinity reoccurring in a volatile fashion. The widening of the Anthropocene reef window (which is not
reecting size and frequency of reefs) corresponds to the ecostratigraphic reef episodes (15b) as outlined in Figure 3.4.3.
Modied from Leinfelder et al. (2012).
The Biostratigraphic Signature of the Anthropocene 129
(vertical labelled lines),
(black rectangles); bold
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composition, indicators for shifts in terrigenous
runoff or even oxygen concentration, can be used to
establish different patterns of reef growth. This in turn
allows the detection of sea-level uctuations and
enables their use for chronostratigraphic purposes
(e.g., Sarg 1988; Schlager 1992; Leinfelder 1997,
2001; Leinfelder & Wilson 1998; Leinfelder & Schmid
2000; Leinfelder et al. 2002).
It is only in Cenozoic reefs that direct proxies for
sea surface temperature (SST) can be derived from
oxygen and Ca/Sr isotopes (Figure 3.4.2) and seawater
alkalinity from boron isotopes (for pH) (see Section
5.3). Such proxies are recorded in the annual skeletal
growth bands, which can be either directly dated by
14
C measurements, dated by backward counting of
growth rings, or correlated via characteristic waxing-
waning sets of growth rings, as done with tree rings.
SSTs appear to be recorded with a mostly negligible
vital effect on isotopic composition within the
aragonitic skeleton. Nevertheless, there are
restrictions: oxygen isotopes are particularly
dependent on salinity and might also need other
corrections, such as the amount of isotopically light
water being bound in polar ice caps, while the possible
effects of diagenesis also need to be taken into
account. For coral skeletons, stable isotopes are the
key instruments for identifying global or regional
shifts in seawater temperature for the Cenozoic,
chiey in the Neogene, and may also be used as
stratigraphic tools (e.g., Fairbanks & Matthews 1978;
Ahmad et al. 2011; Chappell & Shackleton 1986;
Zinke et al. 2014; Tierney et al. 2015; DeLong et al.
2016).
Although most present tropical reefs are dependent
on photosymbiosis, letting them ourish within a
narrow range of warm, superoligotrophic (with low
nutrients and high dissolved oxygen) waters, there are
still some modern reefs that, from their organic
composition and environmental adaptations,
resemble geologically much older reefs and hence are
termed atavisticby Leinfelder et al. (2012). Such
Figure 3.4.2 Comparison of SST records between the
years 1600 and 2000 CE as reconstructed from coral
skeletons (mostly using
16
O/
18
O isotope and Ca/Sr ratios)
from different tropical reefal settings, allowing
correlation of SSTs across oceans. Shown are averages
within the ENSO (three to seven) year band, (a)(d); (e)
shows a comparison with instrumental data (from
Tierney et al. 2015).
130 3.4 Using the State of Reefs for Anthropocene Stratigraphy: An Ecostratigraphic Approach
Sr/Ca
Sr/Ca
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reefs are composed of more robust, more resilient,
more adaptable or even Lazarus-type relic taxa,
which allow them to thrive in high-sediment and -
nutrient settings, deeper waters and generally
unstable environmental regimes. Atavistic reefs and
Lazarus-reef taxa can be expected to become more
common as the Anthropocene progresses (see
Section 3.4.3).
3.4.2 The Present Situation of
Tropical Reefs with Regard to
Stratigraphic Correlation
Despite todays narrow superoligotrophic reef
window, Quaternary tropical coral reefs are basically
resilient ecosystems that can tolerate or easily recover
from occasional temporary disturbances. Damage
caused by a tropical cyclone or coral bleaching due to
temperature peaks is reparable if sufcient
regeneration time is available before a new
disturbance occurs, so long as the overall ecological
conditions for reef growth are in order. As in the
grazing of savannas, an occasional storm may even
foster biodiversity by providing fresh substrata to
larvae of slower-growing corals. Other corals, such as
some acroporoids, even use fracturing for vegetative
reproduction and more extensive dissemination, with
coral branch fragments becoming cemented to the
ground by surviving polyps and restarting colonial
growth. Such natural resilience is rapidly diminishing
in most recent coral reefs. Overshing, water
pollution (owing to runoff of soil, fertilisers, other
chemicals, plastic particles, etc.), global warming and
the decreasing pH of higher-latitude tropical marine
waters have dramatically increased the vulnerability
of reefs (e.g., Wells & Hanna 1992; Hoegh-Guldberg
2007; Heiss & Leinfelder 2008; Burke et al. 2011;
Schoepf et al. 2015; Hughes et al. 2003, 2017a).
Hence, natural perturbations, such as El Niñotype
temperature peaks (discussed in Section 6.1), have
stronger and much more widespread ecological
effects. It is highly probable that the increase in the
frequency and intensity of both high-temperature and
storm events is caused by the anthropogenic rise of
atmospheric CO
2
(e.g., GFDL 2017; Reed et al. 2015).
In addition, rainfall associated with tropical cyclones
may result in pulses of strongly increased inux of
soil particles, nutrients and pesticides from agriculture
in the hinterland, as frequently happens on the Great
Barrier Reef (Brodie et al. 2013). This results in
eutrophication peaks in the oligotrophic tropical reef
ecosystem, leading to blooms of planktic algae and
severe overgrowth of corals by soft lamentous
benthic algae. Owing to the overall weakening of the
reef system by these factors, corals are more
vulnerable to natural diseases. Stressed coral reefs
have difculty in recovering, especially if individual
events such as hurricanes or bleaching events coupled
with temperature peaks occur too often. In a
stratigraphic context, ecological perturbation events
in coral reefs can affect vast areas and occur
penecontemporaneously in different regions or even
globally across the entire tropical zone, and hence
they should be stratigraphically correlatable.
After severe bleaching events in 1997/1998,
2002 and partly in 2010, 2016 was one of the
strongest bleaching events in the Great Barrier Reef
(GBR). About 90% of the surveyed 1,156 individual
reefs of the GBR complex were affected, and >60% of
all corals were bleached. There was no recovery time,
because another devastating bleaching related to a
renewed El Niño event took place in 2017, possibly
representing the most pronounced coral bleaching in
the history of the GBR. It is reported that about 70%
of the shallow-water corals around the tourist town
of Port Douglas died, with similar values around
Cairns and Townsville (Hughes et al. 2017a; GBRMPA
2017). In addition, the devastating effects of Cyclone
Debbie, which swept across Australia in March
2017, not only smashed many reef regions into rubble
but once again swept mud, fertilisers and pollutants
into the reef regions (Robertson 2017). Hence, as with
earlier bleaching events, especially the 1997/1998
event, the 2016 bleaching event can be correlated not
only across the major part of the GBR (e.g., Cantin &
Lough 2014) but also across the Indian Ocean, other
The Biostratigraphic Signature of the Anthropocene 131
event took place in 2017, possibly
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parts of the Pacic and the Caribbean. There are
many studies on how bleaching events are recorded
not only in the SST-recording isotopic oxygen
signal but also in growth patterns or isotopic
proxies of reduced calcication (e.g., Pereira et al.
2015; DeLong et al. 2016; DeCarlo & Cohen 2017), but
using this for interregional to global time-slice
correlations based on coral skeleton characteristics
and proxies is still in its infancy (e.g., Neukom et al.
2014; Tierney et al. 2015; Abram et al. 2016;
Figure 3.4.2 herein).
3.4.3 The Application of Reef Stratigraphy:
Ecostratigraphic Scenarios for the
Anthropocene
3.4.3.1 Ecostratigraphic Scenario 1:
Correlating Reefs in Deteriorating Ecological
Settings (Figure 3.4.3a)
Since stone corals are good recorders of SSTs through
possessing annual skeletal growth bands and
mirroring SSTs in equilibrium conditions via oxygen
or Sr/Ca-isotopes, they can monitor rising SSTs as
long as they are not killed by the heat (e.g., Ahmad
et al. 2011; Tierney et al. 2015; DeLong et al. 2016).
Despite recording only local temperatures, such
measurements can be correlated using growth-ring
counts or other characteristics, such as waxing/
waning patterns of sets of growth rings or even
14
C ages. SST-peak-related bleaching events, as
discussed above, can be correlated across the entire
globe via combining SST proxies and micro-erosion
events across reefs. Storms, if pronounced, especially
as recovery times now are slow, should also be
correlatable across wide areas of reefs via disruptive
surfaces associated with a dominance of reef rubble
within the reefs and lagoonal settings. Overshing
and eutrophication of reefs are resulting in a strong
reduction of reef coral diversity, overgrowth by algal
turfs (which can be fossilised as microbored surfaces),
or macroborings by organisms such as sponges and
bivalves. Interruptions of reef growth, caused by
coastal runoff, may also be discernible and probably
correlatable via cessation of reef growth in
association with biological and physical erosion, as
well as via coatings of terrigenous material.
If anthropogenic greenhouse gases continue to be
emitted at the current rates, even strong attempts at
local or regional reef management or reef protection
will not help prevent highly diverse and structured
coral reefs from disappearing, possibly as early as the
mid-21st century. In such scenarios, ocean
acidication spreading from higher latitudes towards
the equator will prevent coral reefs escapingpoleward
from rapidly rising tropical SSTs (e.g., Hoegh-Goldberg
et al. 1999, 2007, 2009; Hughes et al. 2017a, b).
Escapeto deeper, somewhat cooler waters would also
be largely hindered by these being too turbid because
of the increasing runoff of nutrients creating more
plankton. Nevertheless, it is important to recognise that
coral reefs have survived frequent warmings and
coolings, most of them not rapid, within the
Pleistocene. Furthermore, it is clear that the same
corals that populate the Great Barrier Reef also exist
on the much warmer reefs around New Guinea.
Hence we cannot predict with condence that
present-day reefs will die out completely as the oceans
continue to warm. Given sufcient time, reef
organisms may be able to adapt, although the centres
and patterns of reef growth may well shift in time as
the climate changes.
Relating this reactivity of reefs to an Anthropocene
under business as usualconditions (in terms of
climate change and environmental pollution) would
mean that ecological change of coral reefs relative to
the earlier Holocene should, at least to some extent,
be detectable from the 15th century onwards.
Holocene reefs likely began to transform since
Columbian times (Jackson 1997), especially due to the
onset of intensive shing, often resulting in local to
regional overshing, including that of sea turtles and
sea mammals. These early changes may characterise
the initial anthropogenic imprint on reefs, expressed
in the form of reduced diversity and coral coverage
and subsequently increasing in response to the effects
of growth in population, world trade and
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industrialisation during the mid-20th century
(see Section 7.5).
The suggested base of the Anthropocene around the
mid-20th century is expected to be correlatable across
coral reefs (see Section 7.8.4.2 for use of corals as a
potential medium for the placement of a GSSP) by the
following:
(1) Spikes of radioactive fallout from nuclear bomb
tests preserved in coral skeletons, beginning in the
early 1950s, peaking in the 1960s and continuing
until the 1980s (Waters et al. 2016)
(2) Possibly also enrichment of Pb from industrial
activity, since corals are able to accumulate heavy
metals (e.g., Berry et al. 2013)
(3) An increase of plastic and other anthropogenic
particles trapped in interstitial reef voids and
cavities from the 1950s to present
Younger ecostratigraphic correlation within reefs
might be possible by the following:
(1) The nearly complete disappearance of sea urchins
owing to a pervasive infection in the Caribbean
in the 1980s (Knowlton 2001)
(2) A strong decrease in coral-reef diversities since the
late 1980s/early 1990s, especially with the strong
reduction to near disappearance of Caribbean
acroporoid corals, paralleled by an increase of lter
feeders and boring organisms (e.g., Seemann et al.
2012; Lirmann et al. 2014)
(3) Correlation of the 1997/1998, 2002 and 2016
global bleaching events, using coral skeletons (see
Figure 3.4.2)
(4) Correlation of the onset of invasive species, such
as occurrences of teeth and other skeletal parts
of the lion sh in the Caribbean in the early 21st
century (Schoeld 2009), possibly preservable in
muddy reef lagoons
Despite many efforts to support coral reefs, there is
general scientic agreement that under business as
usualconditions there will be a global demise or severe
reduction of coral reefs somewhere between the middle
and end of the 21st century (Figure 3.4.3a), providing
another important biostratigraphic marker horizon. As
pointed out above, Earth history is no comfort in this
respect, because recovery following global shallow-
water reef extinctions during the Phanerozoic took
place over many millions of years (see Section 3.4.1).
3.4.3.2 Ecostratigraphic Scenario 2:
Using AssistedCoral-Reef Episodes
of the Anthropocene
Some reef researchers see the evolutionary and
epigeneticadaptivity of corals and other reef organisms
as much larger than previously thought, believing that
especially in a combined effort of (1) keeping
atmospheric CO
2
below 450 ppm, (2) extensive
management of reefs (in relation to overshing,
eutrophication, sediment runoff and other pollution as
well as tourist or shipping damage) via marine parks,
and (3) assistedapproaches to enlarge resilience of
coral reefs, there might be progress towards enhancing
coral-reef development during the futureAnthropocene
(see also Section 3.3). There are presently many studies
in the new eld of assisted adaptabilityaiding the
evolution of coral reefs. For example, recovery after
mechanical reef damage, such as tropical storms or the
collision of a ship on a reef, could be assisted by
replanting cultured coral (for an overview see Ferse
2008), although costs would be extremely high on a
larger scale, and long-term success has not yet been
demonstrated. Some coral species are potentially better
adapted to higher water temperatures (Schoepf et al.
2015) or minor acidication (Shamberger et al. 2014),
but these cannot be transplanted into other regions so
far, a restriction which is not fully understood yet. Some
working groups experiment on assisted evolutionin
order to breed resistant species (e.g., van Oppen et al.
2015), but despite some local success (e.g., Zayasu &
Shinzato 2016), so far there have been several setbacks
(Hughes et al. 2017b). Hence the exact temporal onset of
a recovery phase through allowing and enhancing
adaptation and dissemination of substitute corals is
difcult to predict, especially since many factors have to
be taken into account. Here, three aspects are
considered:
The Biostratigraphic Signature of the Anthropocene 133
2017a). Hence
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Figure 3.4.3 Use of Anthropocene coral reefs for ecostratigraphic purposes. Shown are two conceptual scenarios.
(a) Business as usual(BAU) scenario (relative to anthropogenic atmospheric CO
2
emissions); (b) an integrated CO
2
-mitigation/
reef-management/assisted-adaptation scenario. Based on two scenarios taken from Hoegh-Guldberg et al. (2009), as
developed for the Coral Reef Triangle, adapted and extended. In the BAU scenario (a), where atmospheric CO
2
will keep rising,
not even strong management (with or without assistedadaptation) will help coral reefs. The combined mitigation/
management/adaptation scenario (b) will also not see a rapid reversal of the negative trend, but after going through a vale of
tears, it might eventually see the return of fully developed coral reefs.
Ecostratigraphic episodes:
a+b:
(1) Post-Colombian coral-reef phase (pre-Anthropocene, ~1492 to 1950 CE)
(2) Early Anthropocene coral-reef phase (~1950 to 2000 CE), showing increasing, often punctuated decline of coral reefs.
Further subdividable by ecocrisis events such as the near disappearance of Diadema sea urchins in the Caribbean or severe
global bleaching events (dotted line).
(3) Deterioration phase (from 2000 CE onwards): accelerated decline of coral reef, with more frequent punctuation events (e.g.,
2016 bleaching event, dotted line) and rapid deterioration of coral coverage and coral reef occurrences.
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(1) Assisting partial adaptation towards elevated
SSTs and reduced alkalinity : Hughes et al. (2017b)
suggest that whereas scenarios for business as usual
on SSTs and shallow-water ocean acidication
threaten living coral reefs with no chance of survival,
the prognosis would be very different under a
mitigation scenario. SSTs would still continue to rise
slightly in the short term (2010 to 2039 CE), even if
global emissions began to fall, but this would be only
in the range of 0.32
!
C to 0.48
!
C. From 2039 to 2099
CE, SSTs would begin to stabilise, with temperatures
changing, depending on different reef provinces, from
+20
!
C to -0.05
!
C. Consequently, under this low-
emission scenario, coral reefs would experience an
increase of SSTs from 0.30
!
C to 0.68
!
C within the
period from 2010 to the end of the 21st century. The
entire range of temperature increase, including the
past century, would still be near or above 1
!
C, which
is considered to be critical to coral reefs, but at least
some of them could continue to exist. There is
evidence that the geographical range of tropical
species does not contract towards the equator, owing
to acidication, but rather some species expand
towards the subtropics, eeing increases in SST
despite having to handle slight decreases in aragonite
concentration (Pandol2015; Poloczanska et al.
2016). After the mass bleaching event of 1997/1998 in
the Maldives, the reefs changed their composition to
some extent. The more temperature-resistant and
robust scleractinian coral Pavona varians survived
better than Montipora and spread rapidly at the cost
of other species (Loch et al. 2002, 2007). Other corals,
such as Acropora hyacinthus from the Pacic
volcanic island Ofu, can withstand temperatures of up
to 38
!
C by activating special genes (Barshis et al.
2013). However, heat-tolerant corals cannot simply be
transferred from one site to another, as shown, e.g., by
Polato et al. (2010) for larvae of the Caribbean star
coral Montastrea faveolata. Yet the possible exchange
of photosymbionts to more heat-tolerant types (e.g.,
Rohwer & Youle 2010), such as the recently
discovered Symbiodinium C-type S. thermophilium,
which can withstand up to 36
!
C as a symbiont (Hume
et al. 2015), together with a much better
understanding of comparative genomics of reef corals
(e.g., Bhattacharya et al. 2016), gives some hope that
the original, frequently criticised hypothesis of
adaptive coral bleachingmight have at least partial
applicability (Buddemeier & Fautin 1993; Buddemeier
et al. 2004). Hughes et al. (2017b) suggest that provided
a full integrated management of other stressors, such
as overshing and pollution, is introduced by using
new integrated heuristic models, which include
socioeconomic drivers, and provided coral reefs are
allowed and assisted to change their composition, there
may be a chance that functional reefs, albeit partly
with a different set of corals, might persist.
(2) Allowing and supporting an episode of
atavistic reef growth: The future of Anthropocene
coral reefs relies on reducing emissions of CO
2
from
fossil fuels and on new forms of governance,
management and educational concepts (Leinfelder
2017) to limit the human impact on coral reefs.
However, it may also rely on protecting and
Figure 3.4.3 (cont.) BAU scenario (a):
(4a) Tipping-point phase (~2100 ~2130): episode of catastrophic tipping-point-type collapse of all coral reefs,
characterised by dying reefs.
(5a) Post-reef Anthropocene (from about mid-22nd century onwards: largely coral-free Anthropocene oceans, characterised
by biogenic and physical reef reworking.
Mitigation/management/adaptation scenario (b):
(4b) Atavisticreef phase (~20302130 CE): this is the vale of tears-adaptive episode of atavisticand other atypical
coral reefs (see text for explanation).
(5b) Full recovery phase (from ~mid-21st century onwards): renewed episode of large-scale oligotrophic Anthropocene
coral reefs, latest from ~2200 CE onwards (dotted line).
The Biostratigraphic Signature of the Anthropocene 135
Comp. by: 201508 Stage: Proof Chapter No.: 3 Title Name: Zalasiewicz
Date:18/9/18 Time:15:07:20 Page Number: 136
supporting exceptional, in part atavistic reef types
that so far thrive only in places different from the
classic modern oligotrophic reef settings and can
grow under elevated sediment and nutrient inux, as
do the Brazilian Abrolhos reefs (Leão 1982; Leinfelder
& Leão 2000; Leão & Kikuchi 2001), the Iraqi reefs off
the Shatt al Arab (Pohl et al. 2013) and the recently
discovered muddy-water reefs off the Amazon mouth
(Moura et al. 2016). In addition, many classical reefs
in the Caribbean also transform into more nutrient-
and sediment-tolerant low-diversity reef ecosystems,
which also resemble earlier reef types from Earth
history by being less rigid, more meadowlike and more
adapted to elevated coastal-runoff nutrients and heat.
This is shown by the disappearance of acroporoid, as
well as massive corals, in favor of Porites and
Siderastrea corals, soft sponges, large numbers of
brittle stars and many other changes. In the Almirante
Bay of the Caribbean of Panama, such a transition is
recorded from the 1990s (Greb et al. 1996; Berry et al.
2013; Seemann 2013; Seemann et al. 2012. Even more
unexpectedly, reef thickets and bioherms composed of
glass sponges, adapted to elevated nutrients, which
were thought to be extinct at least since the Cretaceous,
have been rediscovered alive in the PacicoffBritish
Columbia (Conway et al. 2001). Having been
threatened by sheries, they recently became fully
protected (Johnson 2017), giving such truly atavistic
reefs from the age of the dinosaurs a chance to thrive
into the future Anthropocene.
(3) Living with the vale of tears: The well-known
study on the Indonesian coral-reef triangle (Hoegh-
Guldberg et al. 2009) also concludes that reefs will
only have a chance if (a) strong management
(including new protection and social-management
schemes, as also outlined by Hughes et al. 2017b) is
implemented and (b) emissions from fossil fuels stop
around 2050. But even in this positive case, reefs
would have to cross a critical vale of tearsphase
(Figure 3.4.3b). Such specialised reefs would only
have a chance to survive if allowed to adapt to the
new conditions in a natural way or helped via human-
assisted adaptation. Such reefs would be of lower
diversity, having fewer ecological niches, and would
probably be short-lived and patchy. They would most
likely not play an important role in coastal protection
and possibly only a reduced role in supporting sh
stocks. However, after such a phase of volatility and
adaptation, reefs might hopefully recover in the late
22nd or 23rd century, possibly forming large,
structured reefs again, though different in taxon
structure relative to Holocene ones.
Combining all these aspects and fusing them into
an ecostratigraphic context, one can assume, under a
mitigation/management/assisted-adaptation
scenario, the following reef-growth-based,
correlatable ecostratigraphic episodes.
(1) The present decline phase might persist till about
20302040 CE, to be followed by a transition stage
to lower diversity, mixotrophic, managed reefs,
which frequently change their characteristics. This
means that coral reefs would continue to grow,
albeit in a completely different form, with the high-
diversity, stable communities retreating in favor of
more volatile, new, short-lived types, with some
just exchanging their key constructive elements,
while many others would show atavistic features,
such as being adapted to higher nutrient levels,
sediment runoff, deeper settings, warmer SSTs or
lower pH. All these reefs would have to be assisted
and redesigned in various ways to assist them to
go through a vale of tears possibly for the next 100,
if not 200, years (Hoegh-Guldberg et al. 2009;
Leinfelder et al. 2012; Hughes et al. 2017b).
(2) With some hope, another extended recovery phase
would set in not earlier than 2100 or 2200 CE,
with coral reefs stabilising and re-diversifying
again in clear, oligotrophic, tropical waters,
returning to robust, resilient and long-lasting
behavior, but nevertheless with a new set of coral-
reef ecologies. Such a change would provide
another easily recognisable ecostratigraphic
boundary (Figures 3.4.1 and 3.4.3b).
136 3.4 Using the State of Reefs for Anthropocene Stratigraphy: An Ecostratigraphic Approach
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19!
References for this section
Abram, N.A., McGregor, H.V., Tierney, J.E., Evans, M.N., McKay, N.P., Kaufman, D.S. and the
PAGES 2k Consortium (Thirumalai, K., Martrat, B., Goosse, H., Phipps, S.J., Steig, E.J.
Halimeda Kilbourne, K., Saenger, C.P., Zinke, J., Leduc, G., Addison, J.A., Mortyn, P.G.,
Seidenkrantz, M.-S., Sicre, M.-A., Selvaraj, K., Filipsson, H.L., Neukom, R., Gergis, J.,
Curran, M.A.J., von Gunten, L. (2016) Early onset of Industrial-era warming across the
oceans and continents. Nature 536, 411-418. doi:10.1038/nature19082
Ahmad, S.M., Padmakumari, V.M., Raza, W., Venkatesham, K., Suseela, G., Sagar, M.,
Chamoli, A., and Rajan, R.S. (2011). High-resolution carbon and oxygen isotope records
from a scleractinian (Porites) coral of Lakshadweep Archipelago. Quaternary
International, 238, 107114. doi:10.1016/j.quaint.2009.11.020
Barshis, D.J., Ladner, J.T., Oliver, T.A., Seneca, F.O.,Traylor-Knowles, N. and Palumbi, S.R.
(2013). Genomic basis for coral resilience to climate change. PNAS, 110/4, 13871392.
DOI: 10.1073/pnas.1210224110
Bhattacharya, D., Agrawa, S., Aranda, M., Baumgarten, S., Belcaid, M., L Drake, J., Erwin,
D.,Foret, S., Gates, R.D., Gruber, D.F., Kamel, B., Lesser, M.P., Levy, O., Jin Liew, Y.,
MacManes, M., Mass, T., Medina, M., Mehr, S., Meyer, E., Price, D.C., Putnam, H.M., Qiu,
H., Shinzato, C., Shoguchi, E., Stokes, A.J.,Tambutté, S., Tchernov, D., Voolstra, C.R.,
Wagner, N., Walker, C.W., Weber, A.P.M., Weis, V., Zelzion, E., Zoccola, D. and Falkowski,
P.G. (2016). Comparative genomics explains the evolutionary success of reef-forming
corals. eLife 2016;5:e13288. DOI: 10.7554/eLife.13288
Berry, K.L.E., Seemann, J., Dellwig, O., Struck, U., Wild, C. & Leinfelder, R.R. (2013) Sources
and spatial distribution of heavy metals in scleractinian coral tissues and sediments from
the Bocas del Toro Archipelago, Panama. Environmental Monitoring and Assessment.
DOI: 10.1007/s10661-013-3238-8
Brodie, J., Waterhouse, J., Schaffelke, B., Kroon, F., Thorburn, P., Rolfe, J., ohnson, J.,
Fabricius, K., Lewis, S., Devlin, M., Warne, M. and McKenzie, L. (2013). Scientific
Consensus Statement. Land use impacts on Great Barrier Reef water quality and
ecosystem condition. 8 p.Reef Water Quality Protection Plan Secretariat, The State of
Queensland. http://www.reefplan.qld.gov.au/about/assets/scientific-consensus-
statement-2013.pdf
Buddemeier, R.W. and Fautin, D. (1993). Coral Bleachig as an Adaptive Mechanism. A
testable hypothesis. Bioscience 43, 320-326.
Buddemeier R.W, Baker A.C, Fautin D.G. and Jacobs J.R. (2004) The adaptive hypothesis of
bleaching. Coral Health and Disease. pp 427444. Springer Publ.
Buggisch, W. (1991). The global Frasnian-Famennian »Kellwasser Event«. Geologische
Rundschau, 80, 4972
Uncorrected version, check references at end of book or ask author
!
20!
Burke, L., Reytar, K., Spalding, M. , Perry, A. Cooper, E., Kushner, B., Selig, E., Starkhouse, B.,
Teleki, K., Waite, R., Wilkinson, C., Young, T. (2011). Reefs at Risk Revisited. 115 pp,
World Resource Institute. http://www.wri.org/publication/reefs-risk-revisited
Cantin, N.E. & Lough, J. (2014). Surviving Coral Bleaching Events: Porites Growth Anomalies
on the Great Barrier Reef. PLoS One. 2014; 9(2): e88720.
Chappell, J. and Shackleton, N.J. (1986). Oxygen isotopes and sea level. Nature, 6093, 137
140.
Clarkson, O., Kasemann, S.A. , Wood, R.A. , Lenton, T.M. , Daines, S.J. , Richoz, S.,
Ohnemueller, F. , Meixner, A., Poulton, S. W. and Tipper, E. T. (2015). Ocean acidification
and the Permo-Triassic mass extinction. Science, 348 (6231), 229-232, DOI:
10.1126/science.aaa0193
Conway, K.W., Krautter, M., Barrie, J.V. and Neuweiler, M. (2001). Hexactinellid sponge
reefs on the Canadian continental shelf: a unique "living fossil". Geoscience Canada
28:71-78.
Copper, P. (2001): Evolution, Radioations, and Exxtinctions in Proterozoic to Mid-Paleozoic
Reefs. In: Stanley, Jr. G.D.The History and Sedimentology of Ancient Reef Systems. Topics
in Geobiology, 17, 89-119.
DeCarlo, T.M. and Cohen, A.L. (2017). Dissepiments, density bands and signatures of thermal
stress in Porites skeletons. Coral Reefs, 6, 749761, doi:10.1007/s00338-017-1566-9
DeLong, K.L., Maupin, C.R., Flannery, J.A., Quinn, T.M. and Shen, C.-C. (2016). Refining
temperature reconstructions with the Atlantic coral Siderastrea siderea. Palaeogeography,
Palaeoclimatology, Palaeoecology, 462, 115, doi: 10.1016/j.palaeo.2016.08.028
Fairbanks, R.G. and Matthews, R.K. (1978). The marine oxygen isotope record in Pleistocene
coral, Barbados, West Indies. Quaternary Research, 10, 181-196
Ferse, S. (2008). Artificial Reefs and Coral Transplantation. Fish Community Responses and
Effects on Coral Recruitment in North Sulawesi/Indonesia. 240 pp, VDM-Verlag
Flügel, E. and Senowbari-Daryan, B. (2001). Triassic Reefs of the Tethys. In: Stanley, Jr. G.D.
(ed.)(2001). The History and Sedimentology of Ancient Reef Systems. Topics in
Geobiology, 17, 217-249.
GBRMA - Great Barrier Reef Marine Park Authority (Australian Government)(2017).
Significant coral decline and habitat loss on the Great Barrier Reef.
http://www.gbrmpa.gov.au/media-room/latest-news/coral-bleaching/2017/significant-
coral-decline-and-habitat-loss-on-the-great-barrier-reef
!
21!
GFDL (Geophysical Fluid Dynamics Laboratory) (2017). Global Warming and Hurricanes
An
Overview of Current Research Results. https://www.gfdl.noaa.gov/global-warming-and-
hurricanes/, accessed: June 2017
Greb, L., Saric, B., Seyfried, H. & R. R. Leinfelder (1996) Ökologie und Sedimentologie eines
rezenten Rampensystems an der Karibikküste von Panamá, Profil, 10, 168 pp., ISSN 0941-
0414
Hautmann, M. (2012). Extinction: End-Triassic Mass Extinction. In: eLS. doi:
10.1002/9780470015902.a0001655.pub3
Heiss, G. & Leinfelder, R.R. (2008): „Fünf vor Zwölf“ Verschwinden die Riffe? In: Leinfelder,
R.R., Heiss, G. & Moldrzyk, U. (eds)(2008): „abgetaucht“. Begleitbuch zur
Sonderausstellung zum Internationalen Jahr des Riffes 2008, 182-197., Konradin-Verlag
(Leinfelden-Echterdingen).
Hoegh-Guldberg, Ove. (1999). Climate Change, Coral Bleaching and the Future of the
World’s Coral Reefs. Mar. Freshwater Res., 50, 83966.
Hoegh-Guldberg, O. Mumby, P.J., Hooten, A.J., Steneck, R.S., Greenfield, P., Gomez, E.,
Harvell, C.D., Sale, P.F., Edwards, A.J., Caldeira, K., Knowlton, N., Eakin, C.M., Iglesias-
Prieto, R., Muthiga, N., Bradbury, R.H., Dubi, A. and Hatziolos, M.E. (2007). Coral reefs
under rapid climate change and ocean acidification. Science, 318, 17371742. Doi:
10.1126/science.1152509
Hoegh-Guldberg, O., Hoegh-Guldberg, H., Veron, J.E.N., Green, A., Gomez, E. D., Lough, J.,
King, M., Ambariyanto, Hansen, L., Cinner, J., Dews, G., Russ, G., Schuttenberg, H. Z., Peña
or, E.L., Eakin, C. M., Christensen, T. R. L., Abbey, M., Areki, F., Kosaka, R. A., Tewk, A.,
Oliver, J. (2009). The Coral Triangle and Climate Change: Ecosystems, People and Societies
at Risk. WWF Australia, Brisbane, 276 pp, http://www.wwf.de/fileadmin/fm-
wwf/Publikationen-PDF/climate_change___coral_triangle_summary_report.pdf
Hofmann, A. (1981). The ecostratigraphic paradigm. Lethaia, 14, 1-7, doi: 10.1111/j.1502-
3931.1981.tb01066.x
Hughes, T.P., Baird, A.H., Bellwood,, D.R., Card, M., Connolly, S.R., Folke, C., Grosberg, R.,
Hoegh-Guldberg, O., Jackson, J.B.J., Kleypas, J., Lough, J.M., Marshall, P., Nyström, M.,
Palumbi, S.R., Pandolfi, Rosen, B. and Roughgarden, J. (2003). Climate Change, Human
Impacts, and the Resilience of Coral Reefs. Science, 301 (5635), 929-933. DOI:
10.1126/science.1085046 929-933
Hughes, T. P., Kerry, J. T., Álvarez-Noriega, M., Álvarez-Romero, J. G., Anderson, K. D., Baird,
A. H., Babcock, R. C., Beger, M., Bellwood, D. R., Berkelmans, R., Bridge, T. C., Butler, I. R.,
Byrne, M., Cantin, N. E., Comeau, S., Connolly, S. R., Cumming, G. S., Dalton, S. J., Diaz-
Pulido, G., Eakin, C. M., Figueira, W. F., Gilmour, J. P., Harrison, H. B., Heron, S. F., Hoey, A.
S., Hobbs, J.-P. A., Hoogenboom, M. O., Kennedy, E. V., Kuo, C.-Y., Lough, J. M., Lowe, R.
J., Liu, G., McCulloch, M. T., Malcolm, H. A., McWilliam, M. J., Pandolfi, J. M., Pears, R. J.,
Pratchett, M. G., Schoepf, V., Simpson, T., Skirving, W. J., Sommer, B., Torda, G.,
!
22!
Wachenfeld, D. R., Willis, B. L. & S. K. Wilson (2017a): Global warming and recurrent mass
bleaching of corals. Nature, 543 (7645), pp. 373-377, doi: 10.1038/nature21707
Hughes, T. P., Barner, M. K., Bellwood, D. R., Cinner, J. E., Cumming, G. S., Jackson, J. B. C.,
Kleypas, J., van de Leemput, I. A., Lough, J. M., Morrison, T. H., Palumbi, S. R., van Nes, E.
H. & M. Scheffer, (2017b). Coral reefs in the Anthropocene. Nature, 546, 8290,
doi:10.1038/nature22901
Hume, B.C.C., D’Angelo, C., Smith, E.G., Stevens, J.R., Burt, J. and Wiedenmann, J. (2015).
Symbiodinium thermophilum sp. nov., a thermotolerant symbiotic alga prevalent in corals
of the world’s hottest sea, the Persian/Arabian Gulf. Scientific Reports, 5, 8562, DOI:
10.1038/srep08562
Jackson, J. B. C. (1997): Reefs since Columbus. Corals Reefs, 16, 23-32.
https://courses.pbsci.ucsc.edu/eeb/bioe147/Readings/Jackson_97.pdf
Johnson, L. (2017). Fisheries minister to announce protection for ancient glass sponge reefs.
9,000 year old reefs expected to be protected by new Marine Protected Area on B.C.
Coast. CBCNews, 15. Feb. 2017, http://www.cbc.ca/news/canada/british-
columbia/leblanc-sponge-announcement-1.3984590
Knowlton, N. (2001). Sea urchin recovery from mass mortality: New hope for Caribbean coral
reefs? Proceedings of the National Academy of Sciences of the United States of America,
98(9), 48224824. http://doi.org/10.1073/pnas.091107198
Leão, Z.M.A.N. (1982): Morphology, geology and developmental history of the southernmost
coral reefs of Western Atlantic, Abrolhos Bank, Brazil. PhD Dissertation, Rosenstiel School
of Marine and Atmospheric Sciences, University of Miami, Florida, USA, 218 p
Leão, Z.M.A.N. and Kikuchi, R. (2001). The Abrolhos Reefs of Brazil. Ecological Studies, 144,
83-92.
Leinfelder, R.R. (1997). Coral reefs and carbonate platforms within a siliciclastic setting:
General aspects and examples from the Late Jurassic of Portugal. Proc. 8th Int. Coral Reef
Symp., 2, 1737-1742, Panama City
Leinfelder, R.R. (2001). Jurassic Reef Ecosystems. In: Stanley, G.D.Jr. (ed), The History and
Sedimentology of Ancient Reef Systems, Topics in Geobiology Series, 17, 251-309.
Leinfelder, R. (2017): Das Zeitalter des Anthropozäns und die Notwendigkeit der großen
Transformation - Welche Rollen spielen Umweltpolitik und Umweltrecht? - Zeitschrift für
Umweltrecht (ZUR), 28, 5, 259-266, Nomos.
http://www.zur.nomos.de/fileadmin/zur/doc/Aufsatz_ZUR_17_05.pdf
Leinfelder, R.R. and Leão, Z.M.A.N. (2000): Increasing Reef Complexity-Decreasing Reef
Flexibility Through Time, and a Unique Exception The Evolutionary Relic Reefs of Brazil.
31st International Geological Congress, Rio de Janeiro, Brazil, Abstract Vol.
!
23!
Leinfelder, R.R. & Nose, M. (1999). Increasing complexity - decreasing flexibility. A different
perspective of reef evolution through time. Profil 17:135-147 (Univ. Stuttgart).
tinyurl.com/reefsthroughtime
Leinfelder, R.R., Seemann, J., Heiss, G.A., & Struck, U. (2012): Could ‘Ecosystem Atavisms’
Help Reefs to Adapt to the Anthropocene? Proceedings of the 12th International Coral
Reef Symposium, Cairns, Australia, 9-13 July 2012 2B Coral reefs: is the past the key to the
future? http://www.icrs2012.com/proceedings/manuscripts/ICRS2012_2B_2.pdf
Leinfelder, R.R. & Schmid, D.U. (2000). Mesozoic Reefal Thrombolites and other Microbolites.
In: Riding, R. (ed.), Microbial Sediments, 289-294, Berlin (Springer)
Leinfelder, R.R., Schmid. D.U., Nose, M. & Werner, W. (2002). Jurassic reef patterns - The
expression of a changing globe. In Flügel, E., Kiessling W. & Golonka, J.
(eds), Phanerozoic Reef Patterns, SEPM Sp.P. 72, 465-520, Tulsa
Leinfelder, R.R. & Wilson, R.C.L. (1998). Third order Sequences in an Upper Jurassic Rift-
Related Second Order Sequence, Central Lusitanian Basin, Portugal. In: Graciansky, P.-C.
de, Hardenbol, J., Jacquin, T. and Vail, P. eds., Mesozioc-Cenozoic Sequence Stratigraphy
of European Basins, SEPM, Sp. Publ., 60, 507-525, Tulsa.
Lirman, D., Schopmeyer, S., Galvan, V., Drury, C., Baker, A. C., & Baums, I. B. (2014). Growth
Dynamics of the Threatened Caribbean Staghorn Coral Acropora cervicornis: Influence of
Host Genotype, Symbiont Identity, Colony Size, and Environmental Setting. PLoS ONE,
9(9), e107253. http://doi.org/10.1371/journal.pone.0107253
Loch, K., Loch, W., Schuhmacher, H. & See, W.R. (2002). Coral recruitment and regeneration
on a Maldivian reef 21 months after the coral bleaching event of 1998. Mar. Ecol., 23:
219-236.
Loch, K., Loch, W. & Anlauf, H. (2007): Der Zustand der Steinkorallen in maledivischen Riffen
und die Regeneration nach dem 1998er Korallenbleichen. Bufus, 37,
http://bufus.sbg.ac.at/Info/Info37/Info37-2.htm
Moura, R. L., Amado-Filho, G. M., Moraes, F. C., Brasileiro, P. S., Salomon, P. S., Mahiques,
M. M., Bastos, A. C., Almeida, M. G., Silva Jr, J. M., Araujo, B. F., Brito, F. P., Rangel, T. P.,
Oliveira, B. C. V., Bahia, R. G., Paranhos, R. P., Dias, R. J. S., Siegle, E., Figueiredo Jr, A. G.,
Pereira, R. C., Leal, C. V., Hajdu, E., Asp, N. E., Gregoracci, G. B., Neumann-Leitão, S.,
Yager, P. L., Francini-Filho, R. B., Fróes, A., Campeão, M., Silva, B. S., Moreira, A. P. B.,
Oliveira, L., Soares, A. C., Araujo, L., Oliveira, N. L., Teiveira, J. B., Valle, R. A. B.,
Thompson, C. C., Rezende, C. E. & F. L. Thompson (2016) An extensive reef system at the
Amazon River mouth. Science Advances, 2 (4), doi: 10.1126/sciadv.1501252
Neukom, R., J. Gergis, D. Karoly, H. Wanner, M. Curran, J. Elbert, F. González-Rouco, B.
Linsley, A. Moy, I. Mundo, C. Raible, E. Steig, Tas van Ommen, T. Vance, R. Villalba, J. Zinke
and D. Frank (2014). Inter-hemispheric temperature variability over the last millennium.
Nature Climate Change, 4, 362367doi:10.1038/nclimate2174.
!
24!
Olóriz, F., Caracuel, J.E. and Rodríguez-Tovar, F.J. (1995). Using Ecostratigraphic Trends in
Sequence Stratigraphy. In: Haq, B.U. (ed.), Sequence Stratigraphy and Depositional
Response to Eustatic, Tectonic and Climatic, 59-85, Springer-Publ. Doi: 0.1007/978-94-
015-8583-5_3
Pandolfi, J. M. (2015): Incorporating Uncertainty in Predicting the Future Response of Coral
Reefs to Climate Change. Annual Review of Ecology, Evolution, and Systematics, 46, 281-
303, doi: 10.1146/annurev-ecolsys-120213-091811
Pereira, N.S., Sial, A.N., Kikuchi, R.K.P., Ferreira, V.P., Ullmann, C.V., Frei, R. and Cunha,
A.M.C. (2015). Coral-based climate records from tropical South Atlantic: 2009/2010 ENSO
event in C and O isotopes from Porites corals (Rocas Atoll, Brazil). Anais da Academia
Brasileira de Ciência, DOI: 10.1590/0001-3765201520150072
Pohl, T., , Al-Muqdadi, S.W., Ali, M.H., Al-Mudaffar Fawzi, N., Ehrlich, H. and Merkel, B.
(2013). Discovery of a living coral reef in the coastal waters of Iraq. Scientific Reports, 4,
4250, DOI: 10.1038/srep04250
Polato, N.R., Voolstra, C.R., Schnetzer, J., DeSalvo, M.K., Randall, C.J., Szmant, A.M., Medina,
M., Baums, I.B. (2010). Location-Specific Responses to Thermal Stress in Larvae of the
Reef-Building Coral Montastraea faveolata. PLoS ONE 5(6): e11221.
doi:10.1371/journal.pone.0011221
Poloczanska, E. S., Burrows, M. T., Brown, C. J., Molinos, J. G., Halpern, B. S., Hoegh-
Guldberg, O., Kappel, C. V., Moore, P. J., Richardson, A. J., Schoeman, D. S. & W. J.
Sydeman (2016). Responses of Marine Organisms to Climate Change across Oceans.
Frontiers in Marine Science, 3 (62), doi: 10.3389/fmars.2016.00062
Reed, A. J., Mann, M. E., Emanuel, K. A., Lin, N., Horton, B. P., Kemp, A. C. & Donnelly, J. P.
(2015). Increased threat of tropical cyclones and coastal flooding to New York City during
anthropogenic era. PNAS, 112 (41), 12610-12615, doi: 10.1073/pnas.1513127112
Robertson, J. (2017). Runoff pollution from Cyclone Debbie flooding sweeps into Great
Barrier Reef. The Guardian 11 April 2017 https://www.theguardian.com/australia-
news/2017/apr/11/run-off-pollution-from-cyclone-debbie-flooding-sweeps-into-great-
barrier-reef (retrieved June 2017)
Rohwer, F. and Youle, M. (2010). Coral reefs in the microbial seas. 201 pp, Plaid Press.
Sarg, J.F. (1988). Carbonate Sequence Stratigraphy. In: Wilgus, C.K., Hastiings, B.S.,
Posamentier, H., Van Wagoner, Y., Ross, C.A. and Kendall, C.G. (eds.), Sea-level changes:
an integrated approach. Soc. Econ. Paleont. Mineral., Sp. Publ., 42, 155-181, Tulsa.
Schlager, W. (1992). Sedimentology and sequence stratigraphy of reefs and carbonate
platforms. Amer. Assoc. Petrol. Geol. Contin. Educ. Course Note Ser., 34, 71 pp., Tulsa.
Schoepf, V., Stat, M., Falter, J. L. & M. T. McCulloch (2015): Limits to the thermal tolerance of
corals adapted to a highly fluctuating, naturally extreme temperature environment,
Scientific Reports, 5, doi:10.1038/srep17639
!
25!
Schofield, Pamela J. (2009) Geographic extent and chronology of the invasion of non-native
lionfish (Pterois volitans [Linnaeus 1758] and P. miles [Bennett 1828]) in the Western
North Atlantic and Caribbean Sea. Aquatic Invasions, 4 (3), 473-479. DOI:
10.3391/ai.2009.4.3.5
Seemann, J. (2013). The use of 13C and 15N isotope labeling techniques to assess
heterotrophy of corals. Journal of Experimental Marine Biology and Ecology, 442 (88), doi:
10.1016/j.jembe.2013.01.004
Seemann, J., Carballo-Bolaños, R., Berry, K.L., González, C.T., Richter, C. & Leinfelder, R.R.
(2012). Importance of heterotrophic adaptations of corals to maintain energy reserves.
Proceedings of the 12th International Coral Reef Symposium, Cairns, Australia, 9-13 July
2012 19A Human impacts on coral reef. Online Publication:
http://www.icrs2012.com/proceedings/manuscripts/ICRS2012_19A_4.pdf
Shamberger, K. E. F., Cohen, A. L, Golbuu, Y., McCorkle, D. C., Lentz, S. J. and Barkley, H.C.
(2014). Diverse coral communities in naturally acidified waters of a Western Pacific reef.
Geophysical Research Letters 41 (2), pp. 499-504, doi: 10.1002/2013GL058489
Sokolov, B.S. (1988). Ekostratigrafiya, yeye mesto i rol' ν sovremennoy stratigrafii, in D. L.
Kaljo and E. R. Klaamann (eds.), Teoriya i opyt ekostratigrafii (The Theory and Practice of
Ecostratigraphy), pp. 9-18; Inst. Geol. AN Eston. SSR, Valgus Press, Tallinn, 1986. (using
translated version: Ecostratigraphy, its place and role in modern stratigraphy,
International Geology Review, 30, (1), 3-10, 1988. Doi:10.1080/00206818809465980
(online 2010)
Stanley, Jr. G.D. (2001a). Introduction to Reef Ecosystems and Their Evolution. In: Stanley, Jr.
G.D. (ed.)(2001b). The History and Sedimentology of Ancient Reef Systems. Topics in
Geobiology, 17, 1-39
Stanley, Jr. G.D. (ed.)(2001b). The History and Sedimentology of Ancient Reef Systems. Topics
in Geobiology, 17, 458 pp.
Tierney, J.E., Abram, N.J., Anchukaitis, K.J. , Evans, M.N. , Giry, C., Kilbourne, K.H., Saenger,
C.P., Wu, H.C. and, J. (2015). Tropical sea surface temperatures for the past four centuries
reconstructed from coral archives. Paleoceanography, 30, 226252,
doi:10.1002/2014PA002717.
Van Oppen, M. J. H., Oliver, J. K., Putnam, H. M. and Gates, R.D. (2014). Building coral reef
resilience through assisted evolution. PNAS, 112 (8), pp. 2307-2313, doi:
10/1073/pnas.1422301112
Veron, J.E.N. (1995). Corals in Space and Time. The Biogeography & Evolution of the
Scleractinia. 321 pp., Comstock/Cornell.
Veron, J.E.N. (2008). Mass extinctions and ocean acidification: biological constraints on
geological dilemmas. Coral Reefs, 27, 459472, DOI 10.1007/s00338-008-0381-8
!
26!
Waters, C.N., Jan Zalasiewicz, Colin Summerhayes, Anthony D. Barnosky, Clément Poirier,
Agnieszka Galuszka, Alejandro Cearreta, Matt Edgeworth, Erle C. Ellis, Michael Ellis,
Catherine Jeandel, Reinhold Leinfelder, J. R. McNeill, Daniel de B. Richter, Will Steffen,
James Syvitski, Davor Vidas, Michael Wagreich, Mark Williams, An Zhisheng, Jacques
Grinevald, Eric Odada, Naomi Oreskes, Alexander P. Wolfe (2016). The Anthropocene is
functionally and stratigraphically distinct from the Holocene. Science, 351 (6269), DOI:
10.1126/science.aad2622
Wells, S. and Hanna, R. (1992). The Greenpeace Book of Coral Reefs. 160 pp., London
(Cameron).
Wood. R. (1999). Reef Evolution. 414 pp Oxford Univ. Press
Zayasu, TY. and Shinzato, C. (2016). Hope for coral reef rehabilitation: massive synchronous
spawning by outplanted corals in Okinawa, Japan. Coral Reefs, 35, 12951295, DOI
10.1007/s00338-016-1463-7
Zinke, J., Loveday, B.R., Reason, C.J.C., Dullo, W.-C., Kroon, D. (2014). Madagascar corals
track sea surface temperature variability in the Agulhas Current core region over the past
334 years. Scienctific Reports, 4, 4393, doi:10.1038/srep04393

Supplementary resource (1)

... Therefore, shallowwater corals most clearly exemplify stratigraphic patterns relevant to the Anthropocene, with two selected as reference sites (see Part An important factor is the current overall decline, and uncertain future, of this stratigraphic archive (Hoegh-Guldberg, 2014;Hughes et al., 2017). There has been a 50% reduction in the abundance of reef-building corals over the past 40-50 years, with potential collapse of whole reef systems in the next few decades, as happened during mass extinction events of the geological past (Hoegh-Guldberg, 2014;Leinfelder, 2019). The robust and fossilisable coral skeletons already formed, however, have good potential to preserve the Anthropocene-related signals already imprinted into them. ...
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The Anthropocene Working Group (AWG) has concluded that the Anthropocene represents geological reality and should be linked with the plethora of stratigraphic proxies that initiate or show marked perturbations at around the 1950s, and should be defined using a Global boundary Stratotype Section and Point (GSSP). We propose formalizing the Anthropocene as series/epoch, terminating the Holocene Series/Epoch with a single Crawfordian stage/age. The GSSP should be located at the level where the primary marker shows a rapid increase in 239+240Pu concentrations (coinciding with a globally recognisable, isochronous signal of the first above-ground thermonuclear tests). The stratigraphic signature of the Anthropocene comprises: a) lithostratigraphic signals, including many new proxies, such as synthetic inorganic crystalline mineral-like compounds, microplastics, fly ash and black carbon, in addition to direct modification through human terraforming of landscape and indirect influences on sedimentary facies through drivers such as climate change; b) chemostratigraphic signals including inorganic and organic contaminants and isotopic shifts of carbon and nitrogen; c) fallout from above-ground nuclear weapons testing; d) stratigraphic effects of climate warming, sea-level rise and ocean acidification; and e) biostratigraphic signals, especially range and abundance changes characterised by unprecedented rates and extents of non-native species introductions, increased population and species extinction and extirpation rates. These correlative markers are present in many kinds of geological deposits around the world. This ubiquity of signals verifies that the Anthropocene can be widely delineated as a sharply distinctive chronostratigraphic unit in diverse terrestrial and marine depositional environments, and reflects a major Earth System change that will have geologically lasting consequences. As background, the Anthropocene was suggested as a new epoch by Paul Crutzen in 2000. The AWG was established in 2009 by the Subcommission on Quaternary Stratigraphy to examine the evidence for the potential inclusion of the Anthropocene in the International Chronostratigraphic Chart (ICC) and, if warranted, to formulate a definition and proposal. Various suggested start dates were considered, and the mid-20th century was found to be the only one associated with an extensive array of effectively globally isochronous geological markers reflecting the ‘Great Acceleration’ of population, industrialization and globalization. Alternative interpretations of the Anthropocene, including as an informal ‘event’, were considered in detail by the AWG and found to be inconsistent with the stratigraphic evidence.
... So gab es langanhaltende Phasen mit extensivem, über Millionen von Jahren anhaltendem Vulkanismus, was mehrfach zu Massensterben und über Hunderttausende von Jahren anhaltender Meeresversauerung führte. Es dauerte dann sogar viele Millionen von Jahren, bis sich die Biosphäre davon wieder erholt hatte (Leinfelder 2019). ...
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Die Menschheit hat ihren gesamten Umgang mit der Natur industrialisiert, um möglichst gut von ihr zu leben, aber auch um sich vor der Unbill der Natur mit technischen Mitteln zu schützen. Sowohl gutes als auch sicheres Leben stehen zwischenzeitlich auf dem Spiel. Um beides weiter zu sichern, müssten wir das Erdsystem so mitgestalten, dass es die Mensch- heit durch seine erdsystemaren Leistungen und Güter dauerhaft mittragen und integrie- ren kann. Die Anthropozän-Analyse zeigt jedoch, dass Klimawandel, Landnutzung, Über- fischung, Verschmutzungen etc. Ausmaße erreicht haben, die den humanen Fortbestand unserer Gesellschaften gefährden. Wir lassen uns durch Fahrzeuge, Maschinen und Geräte die Arbeit abnehmen, was gewaltige Mengen von nicht nachwachsenden Ressourcen und Energie erfordert sowie Unmengen von Abraum und Technikmüll produziert. Eine integ- rative, anthropozäne Sichtweise sieht die Biosphäre als Modell für eine physische Techno- sphäre der Zukunft. Technische Produkte würden nach Gebrauch komplett zerlegt und wie- der neu komponiert – statt Müll gäbe es nur noch recycelte „Kulturtechnik-Nährstoffe“. Der zur Nutzung der Produkte und zum kontinuierlichen Upcycling notwendige Energiehunger könnte wie in der Biosphäre durch erneuerbare Energien gestillt werden. Die hier vorge- stellte faktenbasierte Metabolismus-Metapher könnte ein geeignetes Diskurs- und Kom- munikationsnarrativ im Kontext der kulturellen Nachhaltigkeit darstellen, um die für eine Umgestaltung notwendigen neuen, offenen Denkweisen und Perspektivwechsel einzuüben. Keywords: Anthropozän, Technosphäre, Energie, Produktion, Erdsystem, Metapher, Narrativ
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We synthesize research from complementary scientific fields to address the likely future extent and duration of the proposed Anthropocene epoch. Intensification of human-forced climate change began from about 1970 onwards with steepening increases in greenhouse gases, ocean acidification, global temperature and sea level, along with ice loss. The resulting distinction between relatively stable Holocene climatic conditions and those of the proposed Anthropocene epoch is substantial, with many aspects irreversible. The still-rising trajectory of greenhouse gas emissions is leading to yet greater and more permanent divergence of the Anthropocene from the Holocene Earth System. We focus here on the effects of the ensuing climate transformation and its impact on the likely duration of this novel state of the Earth System. Given the magnitude and rapid rise of atmospheric carbon dioxide (CO2), its long lifetime in the atmosphere, and the present disequilibrium in Earth’s energy budget (expressed as the Earth’s Energy Imbalance, or EEI), both temperatures and sea level must continue to rise – even with carbon emissions lowered to net zero (where anthropogenic CO2 emissions = anthropogenic CO2 removals) – until the energy budget balance is eventually restored. Even if net zero were achieved immediately, elevated global temperatures would persist for at least several tens of millennia, with expected levels of warmth by the end of this century not seen since the early Late Pliocene. Interglacial conditions are likely to persist for at least 50,000 years under already-accumulated CO2 emissions and Earth’s low eccentricity orbit. Continued increases in greenhouse gas emissions are likely to extend that persistence to around 500,000 years, suppressing the pronounced expression of Milankovitch cyclicity typical of the later Pleistocene Epoch. This major perturbation alone is sufficient to justify the Anthropocene as terminating the Holocene Epoch. The wider and mostly irreversible effects of climate change, not least in amplifying reconfiguration of the biosphere, emphasize the scale of this departure from Holocene conditions, justifying the establishment of a new epoch. Given such perspectives, the Anthropocene epoch represents what will become a lasting and substantial change in the Earth System. It is the Holocene Epoch at only 11,700 years duration that will appear as the ‘blip’ in the Geological Time Scale, a brief interval when complex, settled human societies co-existed with, but did not overwhelm, a stable Earth System.
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Abstract: The “Great Acceleration” of the mid-20th century provides the causal mechanism of the Anthropocene, which has been proposed as a new epoch of geological time beginning in 1952 CE. Here we identify key parameters and their diagnostic palaeontological signals of the Anthropocene, including the rapid breakdown of discrete biogeographical ranges for marine and terrestrial species, rapid changes to ecologies resulting from climate change and ecological degradation, the spread of exotic foodstuffs beyond their ecological range, and the accumulation of reconfigured forest materials such as medium density fibreboard (MDF) all being symptoms of the Great Acceleration. We show: 1) how Anthropocene successions in North America, South America, Africa, Oceania, Europe, and Asia can be correlated using palaeontological signatures of highly invasive species and changes to ecologies that demonstrate the growing interconnectivity of human systems; 2) how the unique depositional settings of landfills may concentrate the remains of organisms far beyond their geographical range of environmental tolerance; and 3) how a range of settings may preserve a long-lived, unique palaeontological record within post-mid-20th century deposits. Collectively these changes provide a global palaeontological signature that is distinct from all past records of deep-time biotic change, including those of the Holocene. (The preproof-article is now open access: https://doi.org/10.1016/j.earscirev.2024.104844 )
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1. Einleitung: Die Herausforderungen für die heutigen menschlichen Gesellschaften sind immens, sowohl hinsichtlich der Anzahl der Problemfelder, als auch hinsichtlich ihrer gegenseitigen Bedingtheiten und Wechselwirkungen sowie ihrer möglichen Lösungsansätze. Vieles davon sind Zukunftsaufgaben, die jetzt begonnen, aber über einen größeren Zeitraum verfolgt werden müssen und in aller Regel nicht in einem „Weiter wie bisher“-Pfad gelöst werden können. Das Spektrum der Problemkreise reicht von Klima- und Umweltkrise, über soziale Ungerechtigkeiten und Ungleichheiten (wie Hunger, Arbeit, Bildung, Sozialsysteme), neuen Krankheiten und Pandemien bis hin zu Wissenschaftsleugnung, zunehmender Demokratiefeindlichkeit und sich wieder stark ausweitenden kriegerischen Auseinandersetzungen. Zum Umgehen und Lösen derartiger, in aller Regel überaus komplexer Problemfelder ist neben systemischem Denken, also dem Erkennen und Berücksichtigen der Vernetztheit und der Wechselwirkungen unterschiedlicher Problematiken, vor allem eine bessere individuelle und gesellschaftliche Zukunftskompetenz im Sinne einer Futures Literacy1 notwendig. Auch hierbei sind wieder Verknüpfungen und Wechselwirkungen sowie deren Dynamik wesentlich. Nur mit dem Erkennen und einer systemischen Analyse des Zustands sowie der regionalen und zeitlichen Skalierung der heutigen Situation ist Futures Literacy erreichbar. Diese sollte wiederum auch Wissen aus der Analyse historischer und erdgeschichtlicher Abläufe im Sinne eines „Aus der Vergangenheit und Gegenwart für die Zukunft lernen“ integrieren. Lehren aus der Vergangenheit müssen allerdings unterschiedliche Zeitskalen korrekt berücksichtigen; sie stellen damit zeitskalenbasierte Retrospektiven dar. Außerdem weist der Plural „Futures“ (Zukünfte) auch auf die Notwendigkeit hin, auch mehrere Zukunftsperspektiven in verschiedenen Szenarienmöglichkeiten denken zu lernen. Der Mehrebenen-Ansatz des Anthropozän-Konzepts erscheint zur Verbindung all dieser Bereiche als Lehr-, Lern- und Handlungsgrundlage besonders geeignet. So basiert das Konzept zum Ersten auf der systemischen Analyse der Situation, der Wechselwirkungen und der Dynamik des heutigen Erdsystems. Das Erdsystem wird hierbei in der notwendigen erweiterten Form, also unter Einbindung, Gleichstellung und Berücksichtigung der gegenseitigen Interaktion der Anthroposphäre mit den Natursphären (Atmosphäre, Hydrosphäre, Biosphäre, Pedosphäre, Lithosphäre, z.T. mit weiteren Unterteilungen und Erweiterungen) analysiert. Zum Zweiten ist der erdgeschichtliche Aspekt in Hinblick auf die Relevanz für das Heute und Morgen konzeptionell mit integriert (Tiefenzeitprozesse und ihre Bedeutung für heute, etwa für Lebensentwicklung, Bodenschätze, geopolitische Aspekte etc.), genauso wie die Behandlung neuartiger menscheninduzierter Ablagerungen (Technosphäre, Technofossilien, neue anthropogene Erosions- und Sedimentationsabläufe und ihre Auswirkungen) sowie die Bedeutung des Anthropozäns als neue erdgeschichtliche Epoche. Zum Dritten ergibt sich aus der erdsystemaren und geologisch-stratigraphischen Analyse konsequenterweise eine Metaebene der Zukunftsverantwortung, die auf diesen beiden analytischen Ebenen aufbaut und auch die Polyperspektivität von Wahrscheinlichkeiten, Möglichkeiten und Wünschbarkeiten impliziert. Der Fokus dieses Beitrags liegt damit auf der Notwendigkeit und Machbarkeit einer Verknüpfung unterschiedlich skalierter Zeitprozesse mit polyperspektivischen Zukunftsszenarien und Wegen dorthin. Dazu ist es sinnvoll, auf die weithin vernachlässigte Behandlung des Begriffs Zeit, insbesondere zeitliche Dynamiken einzugehen sowie Zukunftsforschung und polyperspektivische Zukunftsszenarien-Ansätze kurz vorzustellen, um aus beidem dann eine Verbesserung des Zeitbewusstseins und des Vorstellungsvermögens zu erreichen und damit integratives und polyperspektivisches Denken einzuüben. Das Angehen von Zukunftsherausforderungen kann dann mit dem Imaginieren und Antizipieren mittels narrativem Erzählen und Visualisieren beginnen und über gemeinschaftliches Konzipieren, Ausprobieren und möglicherweise auch Umsetzen von Lösungsansätzen oder gar ganzer Lösungsportfolios im eigenen oder auch erweiterten Umfeld weitergeführt werden. Derartige Denk- und Experimentieransätze können in jedem Alter, gerade auch schon im Kindesalter beginnen und dann lebenslang weitergeführt werden. Es wird erwartet, dadurch einen wesentlichen Beitrag zur Entwicklung bzw. Optimierung einer persönlichen und gesellschaftlichen Futures Literacy zu leisten.
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Leinfelder, R. (2019): Das Anthropozän - Die Erde in unserer Hand.- In: Schwinger, E. (ed.) Das Anthropozän im Diskurs der Fachdisziplinen, . S.-23-46 Weimar bei Marburg (Metropolis-Verlag, ). (For more info see https://www.metropolis-verlag.de/Das-Anthropozaen-im-Diskurs-der-Fachdisziplinen/1394/book.do )
Preprint
Leinfelder, R. (2019, in press): Das Anthropozän - Die Erde in unserer Hand.- In: Schwinger, E. (ed.) Das Anthropozän im Diskurs der Fachdisziplinen. Weimar bei Marburg (Metropolis-Verlag, ISBN 978-3-7316-1394-7). (For more info see https://www.metropolis-verlag.de/Das-Anthropozaen-im-Diskurs-der-Fachdisziplinen/1394/book.do )
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Transcriptome and genome data from twenty stony coral species and a selection of reference bilaterians were studied to elucidate coral evolutionary history. We identified genes that encode the proteins responsible for the precipitation and aggregation of the aragonite skeleton on which the organisms live, and revealed a network of environmental sensors that coordinate responses of the host animals to temperature, light, and pH. Furthermore, we describe a variety of stress-related pathways, including apoptotic pathways that allow the host animals to detoxify reactive oxygen and nitrogen species that are generated by their intracellular photosynthetic symbionts, and determine the fate of corals under environmental stress. Some of these genes arose through horizontal gene transfer and comprise at least 0.2% of the animal gene inventory. Our analysis elucidates the evolutionary strategies that have allowed symbiotic corals to adapt and thrive for hundreds of millions of years.
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Reef development throught time is characterized by increasing complexity of modular reef structure. Following microbial and parazoan reef modules are Phanerozoic calcifying metazoan and photosymbiontic metazoan modules, as well as the largely Cenozoic coralline algal module. This increasing modular complexity was accompanied by a decreasing reef flexibility towards environmental factors. As an example, Jurassic photosymbiontic coral reefs still preferred to thrive in mesotrophic settings, owing to the lower effectivity of the photosymbiosis between corals and unicellular algae. Contrasting, modern tropical coral reefs have evolutionary narrowed their tolerances towards increased nutrient and, associatedly, terrigeneous influx, which is related to the perfection of the symbiontic system. As a consequence, modern coral reefs are worldwide under stress, whenever increased, and persistent, influx of nutrients and silics occurs. A partial exception to this rule are the modern Brazilian coral reefs which are unique in a way that they probably tolerate more silics and associated nutrients than any other coral reef today. This appears to be (partially) due to the fact that the Brazilian represent "evolutionary relics" from the Tertiary, more precisely the robust part of it, whereas the other taxa became extinct during the Pleistocene. Pleistocene extinction also affected all other Atlantic reefs but robust relics were subsequently substituted by surviving modern forms such as the acroporoids, which did not reach the Brazilian reefs settings owing to the influence of the turbid Amazonas waters. Hence, the Brazilian reefs represent a unique insight to the wider reef window of the lost Tertiary world.
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Coral reefs support immense biodiversity and provide important ecosystem services to many millions of people. Yet reefs are degrading rapidly in response to numerous anthropogenic drivers. In the coming centuries, reefs will run the gauntlet of climate change, and rising temperatures will transform them into new configurations, unlike anything observed previously by humans. Returning reefs to past configurations is no longer an option. Instead, the global challenge is to steer reefs through the Anthropocene era in a way that maintains their biological functions. Successful navigation of this transition will require radical changes in the science, management and governance of coral reefs.
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The skeletons of many reef-building corals are accreted with rhythmic structural patterns that serve as valuable sclerochronometers. Annual high- and low-density band couplets, visible in X-radiographs or computed tomography scans, are used to construct age models for paleoclimate reconstructions and to track variability in coral growth over time. In some corals, discrete, anomalously high-density bands, called “stress bands,” preserve information about coral bleaching. However, the mechanisms underlying the formation of coral skeletal density banding remain unclear. Dissepiments—thin, horizontal sheets of calcium carbonate accreted by the coral to support the living polyp—play a key role in the upward growth of the colony. Here, we first conducted a vital staining experiment to test whether dissepiments were accreted with lunar periodicity in Porites coral skeleton, as previously hypothesized. Over 6, 15, and 21 months, dissepiments consistently formed in a 1:1 ratio to the number of full moons elapsed over each study period. We measured dissepiment spacing to reconstruct multiple years of monthly skeletal extension rates in two Porites colonies from Palmyra Atoll and in another from Palau that bleached in 1998 under anomalously high sea temperatures. Spacing between successive dissepiments exhibited strong seasonality in corals containing annual density bands, with narrow (wide) spacing associated with high (low) density, respectively. A high-density “stress band” accreted during the 1998 bleaching event was associated with anomalously low dissepiment spacing and missed dissepiments, implying that thermal stress disrupts skeletal extension. Further, uranium/calcium ratios increased within stress bands, indicating a reduction in the carbonate ion concentration of the coral’s calcifying fluid under stress. Our study verifies the lunar periodicity of dissepiments, provides a mechanistic basis for the formation of annual density bands in Porites, and reveals the underlying cause of high-density stress bands.
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The evolution of industrial-era warming across the continents and oceans provides a context for future climate change and is important for determining climate sensitivity and the processes that control regional warming. Here we use posted 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account.
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Developing coral-based temperature reconstructions for a particular coral species requires determining the optimal sampling path orientation and resolution for geochemical analysis to avoid sampling artifacts and to increase reproducibility. Furthermore, a robust coral archive should have high intracolony and intercolony reproducibility for determining the common environmental signal. Here we assessed sampling path orientation and sampling resolution for Siderastrea siderea colonies within the Dry Tortugas National Park in the Gulf of Mexico (24°42′N, 82°48′W) to determine the optimal sampling protocol and to assess reproducibility of coral Sr/Ca, δ¹⁸O, and δ¹³C. We identified a sampling artifact due to extracting samples from the coral columella resulting in cold bias up to 5.2 °C in coral Sr/Ca. We found no shift to higher coral Sr/Ca values (i.e., colder) for years with a 50% reduction in average extension rate (2.1 mm year− 1) or for sampling along paths up to 70° off the vertical axis of the colony. Our sampling resolution comparison (1900–1993) indicated that the resolution of ~ 6 samples year− 1 used in a previous study for coral Sr/Ca and δ¹⁸O may not capture seasonal extremes and thus produces muted seasonal cycles, but that resolution is not biased towards one season. Reproducibility or average deviations, assessed using absolute differences (AD) and root mean square (RMS), among the monthly resolved coral Sr/Ca records for intracolony to intercolony comparisons were within 2σ of our analytical precisions. Average deviations were reduced by 19 to 61% when assessing interannual variability (36-month smoothed and mean annual) suggesting that subannual dating uncertainties (i.e., assigning a coral Sr/Ca value to a particular month) were the largest source of error in our monthly resolved coral Sr/Ca reconstruction. Similarly, coral δ¹⁸O was reproducible within 2σ of our analytical precision (AD = 0.10‰ and RMS = 0.07‰); however, coral δ¹³C and linear extension records were not reproducible. Our assessment of coral geochemical variations from multiple S. siderea colonies suggests this species is suitable for paleoclimatic reconstructions, including subfossil corals and microatoll colonies that grow laterally.